DevTools: Add JSDoc for static methods, fix JSDoc types and induced errors

Source/devtools/front_end/timeline/TimelineView.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 635 matching lines @@
          * @return {number}
          */
         function compareEndTime(value, task)
         {
             return value < task.endTime() ? -1 : 1;
         }
 
         var taskIndex = insertionIndexForObjectInListSortedByFunction(startTime, tasks, compareEndTime);
 
         var foreignStyle = "gpu-task-foreign";
-        var element = container.firstChild;
+        var element = /** @type {?Element} */ (container.firstChild);
         var lastElement;
         var lastLeft;
         var lastRight;
 
         for (; taskIndex < tasks.length; ++taskIndex) {
             var task = tasks[taskIndex];
             if (task.startTime() > endTime)
                 break;
 
             var left = Math.max(0, this._calculator.computePosition(task.startTime()) + barOffset - widthAdjustment);
@@ skipping 428 matching lines @@
         if (matchInfo)
             WebInspector.highlightSearchResult(this.element, matchInfo.index, matchInfo[0].length, domChanges);
     },
 
     dispose: function()
     {
         this.element.remove();
     },
 
     /**
-     * @param {!Event} event
+     * @param {?Event} event
      */
     _onExpandClick: function(event)
     {
         this._record.setCollapsed(!this._record.collapsed());
         this._scheduleRefresh();
         event.consume(true);
     },
 
     /**
      * @param {?Event} event
@@ skipping 178 matching lines @@
             this._element.classList.remove("hidden");
         } else
             this._element.classList.add("hidden");
     },
 
     _dispose: function()
     {
         this._element.remove();
     }
 }